If the disable button isn’t
visible, you have to press “uninstall updates” first. Then go back
to step 5

To enable it again:

Once you’ve disabled the app, it will be hidden from your phone as if
it were never there. The great news is if you ever wanted it back, all
you have to do is the same process but “enable” it instead. Just to
let you know, disabled apps show up at the very bottom of the app list
(not in alphabetical order) if you ever wish to re-enable it.

Update:

To disable user installed apps I use this aswesome software called Titanium backup pro (needs root). Freezing app i.e. disabling app is only one of its many features.

To freeze one app:

Open Titanium backup pro

Go to Backup and Restore tab

Find you app and click it

Choose freeze from the menu

To restore click defrost instead of freeze

Note: Freezing app still consumes space.

I personally use this to freeze heavy app like Skype. Application settings like username and password aren't lost in this way.